Pangaea: the super continent from which the 7 continents were made from. Continental drift: the force that moved the continents. Fossil: any trace of an ancient organism that has been preserved in rock.
The Theory of Continental Drift
Alfred Wegner's Hypothesis
All the continents had once been joined together in a single landmass and have since drifted apart.
Pangaea
means "all lands"
formed 300 million years ago
slowly broke apart into 7 great landmasses now known as the continent
Evidence from landforms
Mountain ranges
A mountain range running from east to west in South Africa lines up with one in Argentina
Coal fields
European coal fields match up with coal fields in North America.
Evidence from fossils
Glossopetris
India
Africa
South America
Australia
Antarctica
convinced Wegner that the continents were once united as on single landmass because Glossopetris's seed like structures could not have traveled long distances or have crossed the ocean.
Evidence from Climate
Spitsenberg
lies in the Artic Ocean north of Norway
tropical plant fossils have been found
Wegner concluded that Spitsenberg was near the equator
South Africa
Deep scratches in rocks showed that continental glaciers once covered Africa
Africa's climate is too mild for glaciers
Thus Wegner concluded that South Africa was closer to the North Pole
Scientists reject Wegner's Theory
did not provide a satisfactory explanation about what forces push or pull the continents.
Table of Contents
1.3 Drifting Continents
Vocabulary
Pangaea: the super continent from which the 7 continents were made from.
Continental drift: the force that moved the continents.
Fossil: any trace of an ancient organism that has been preserved in rock.
The Theory of Continental Drift
Alfred Wegner's Hypothesis
Pangaea
Evidence from landforms
Evidence from Climate
Scientists reject Wegner's Theory